The slide is topped off with adjustable combat night sights while the frame is outfitted with a magwell for fast smooth reloads. The frame and slide of the STX are machined to exacting tolerances and hand-fitted to insure reliability and performance. The frame features 25-line per inch checkering on the front strap û while the mainspring housing has 20-line per inch checkering. Like all SIG SAUER products the 1911 STX pistol contains only premium internal parts including a match grade barrel, hammer/sear set and trigger. For safety, the 1911 STX features a beavertail grip safety, extended ambidextrous thumb safety and firing pin safety.